/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.flowable.eventregistry.spring.kafka;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import org.flowable.eventregistry.api.OutboundEvent;

/**
 * @author Filip Hrisafov
 */
public class RoundRobinKafkaPartitionProvider implements KafkaPartitionProvider {

    protected final List<Integer> partitions;
    protected final AtomicInteger counter;

    public RoundRobinKafkaPartitionProvider(List<Integer> partitions) {
        this.partitions = partitions;
        this.counter = new AtomicInteger(0);
    }

    @Override
    public Integer determinePartition(OutboundEvent<?> outboundEvent) {
        int nextValue = counter.getAndIncrement();
        int availablePartitions = partitions.size();
        return partitions.get(Math.abs(nextValue) % availablePartitions);
    }
}
